Multilayer Optical Read-Only-Memory Disk Applicable to Blu-ray Disc Standard Using a Photopolymer Sheet with a Recording Capacity of 100 GB

We have been investigating a multilayer optical disk applicable to Blu-ray Disc (BD) standard using a photopolymer (2P) sheet in order to realize a recording capacity of 100 GB on a 12-cm-diameter disk. We had already developed a 2P sheet utilizing the multilayer disk. In this study, we developed a BD-type quad-layer disk using the 2P sheet, and investigated readout signals from each layer. The jitter values of layer 0 (L0), layer 1 (L1), layer 2 (L2) and layer 3 (L3) in the quad-layer disk were 6.5%, 7.1%, 7.3% and 6.6%, respectively. According to the analysis of the components of jitter values, the main factor behind the deterioration of jitter values is the crosstalk from adjacent layers. However, the jitter value of each layer was sufficient to reproduce the recorded data. From these results, we proved the feasibility of realizing the BD-type multilayer read-only-memory (ROM) disk with the recording capacity of 100 GB.